Mayor Annise Parker imposed mandatory furloughs for many workers last year because of a budget crisis. As an elected official, Sullivan was not required to take the unpaid days off, but he and most council members did so.

"I don't qualify because I did the right thing by taking voluntary furlough days," Sullivan said. "I don't regret having taken them at all."

Sullivan announced his resignation early so the city can put the race for his successor on the November election ballot instead of incurring the expense of a special election. Sullivan initially said that resignation would be effective Jan. 1. When he submitted his resignation letter in July, he made the effective date Jan. 2.